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Source: ONE News
A new test can accurately detect Alzheimer's disease in its
earliest stages, before dementia symptoms surface and widespread
damage occurs, US researchers said.
The test, which measures proteins in spinal fluid that can point to
Alzheimer's, was 87% accurate at predicting which patients with
early memory problems and other symptoms of cognitive impairment
would eventually be diagnosed with Alzheimer's, they said.
"With this test, we can reliably detect and track the progression
of Alzheimer's disease," said Leslie Shaw of the University of
Pennsylvania School of Medicine, whose study appears in the Annals
of Neurology.
Such tests, which look for so-called biomarkers of disease, can
help researchers' better focus trials of Alzheimer's treatments,
Shaw said.
The test may also lead to better strategies to keep mild memory
impairments from progressing into full-blown Alzheimer's disease, a
fatal, mind-robbing ailment that is the most common form of
dementia in the elderly, he added.
Many teams have been seeking ways to diagnose Alzheimer's in its
early stages, which would allow doctors to give people drugs aimed
at slowing the disease.
Shaw and colleagues set out to create a standardized test that
focuses on levels of two classic hallmarks of Alzheimer's in the
brain: amyloid beta protein, which forms sticky brain plaques, and
abnormal levels of the protein tau, which forms fibrous tangles in
the brain.
"What we are measuring is the amount of the tau protein and the
concentration of the amyloid beta42 polypeptide," Shaw said in a
telephone interview.
Test also rules out disease
The team evaluated spinal fluid taken from 410 patients who were
part of a large Alzheimer's study.
They found people with low concentrations of amyloid beta42 were
more likely to develop Alzheimer's disease, presumably because the
protein was accumulating in plaques in the brain.
They also found people with high levels of tau in their spinal
fluid were more likely to develop the disease.
"The release of tau into the fluid compartment is thought to be
the result of the dying of the nerve cells. They release their
contents," Shaw said.
He said these two measures accurately predicted which patients with
memory problems would develop Alzheimer's disease in 87% of the
cases.
The test also ruled out the disease in 95.2% of the
volunteers.
Shaw said the findings are encouraging both for patients and for
drug companies, which may finally have a way diagnose the disease
early on.
"The general consensus is you are going to have the best chance to
improve Alzheimer's disease if you can catch it early, when there
is more brain function there to preserve," he said.
An estimated 26 million people have Alzheimer's globally and
experts predict this number will grow to 106 million by 2050.
